Elevator tension member

ABSTRACT

A belt for suspending and/or driving an elevator car includes a tension member extending along a length of the belt, the tension member including a plurality of fibers bonded in a first polymer matrix, the plurality of fibers extending parallel to and discontinuous along a length of the belt and arranged with one or more lengthwise extending gaps between lengthwise adjacent fibers. A jacket substantially retains the tension member. A method of forming a tension member for an elevator system belt includes arranging a plurality of fibers into a fiber bundle. The plurality of fibers extend parallel to a length of the belt and have one or more lengthwise extending gaps between lengthwise extending fibers. The plurality of fibers is bonded to a first polymer matrix.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 62/215,390, entitled “Elevator Tension Member”, filed Sep. 8, 2015,under 35 U.S.C. §119(e), and which is incorporated herein by referencein its entirety.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to tension members such asthose used in elevator systems for suspension and/or driving of theelevator car and/or counterweight.

Traction-driven elevator belts are typically constructed using tensionmembers, such as steel cords. More recent developments in the area ofcomposites include the use of continuous synthetic fibers such as carbonfiber, glass fiber and/or organic aramid or polyimide fiber to provide agreater strength to weight ratio than steel. Although a belt withcontinuous carbon fiber and thermoset resin will provide improvedstrength to weight advantages compared to steel cord belt, significantperformance and durability challenges exist. For example, the rigidconstruction is contrary to the desire for a flexible belt capable ofmany thousands of bending cycles without brittle or fatigue failure inthe field.

BRIEF SUMMARY

In one embodiment, a belt for suspending and/or driving an elevator carincludes a tension member extending along a length of the belt, thetension member including a plurality of fibers bonded in a first polymermatrix, the plurality of fibers extending parallel to and discontinuousalong a length of the belt and arranged with one or more lengthwiseextending gaps between lengthwise adjacent fibers. A jacketsubstantially retains the tension member.

Additionally or alternatively, in this or other embodiments the tensionmember further includes a plurality of fiber bundles secured to oneanother via a second polymer matrix, each fiber bundle including aplurality of fibers bonded in the first polymer matrix.

Additionally or alternatively, in this or other embodiments the secondpolymer matrix material is different from the first polymer matrixmaterial.

Additionally or alternatively, in this or other embodiments the tensionmember has a fiber density by volume of between 30% and 70%.

Additionally or alternatively, in this or other embodiments the fiberbundle includes fibers of non-uniform cross-sectional sizes and/orlengths.

Additionally or alternatively, in this or other embodiments the beltincludes one or more layers of fibers extending nonparallel to thelength of the belt.

Additionally or alternatively, in this or other embodiments the one ormore layers are disposed at an outermost belt surface.

Additionally or alternatively, in this or other embodiments theplurality of fibers are formed from one or more of carbon, glass,polyester, nylon, aramid or other polyimide materials.

Additionally or alternatively, in this or other embodiments the firstpolymer matrix is formed from a thermoset material or a thermoplasticmaterial

Additionally or alternatively, in this or other embodiments the belt hasan aspect ratio of belt width to belt thickness of greater than or equalto 3:2, with a plurality of tension members arranged across the beltwidth.

In another embodiment, an elevator system includes an elevator car, oneor more sheaves and one or more belts operably connected to the car andinteractive with the one or more sheaves for suspending and/or drivingthe elevator car. Each belt of the one or more belts includes a tensionmember extending along a length of the belt, the tension memberincluding a plurality of fibers bonded in a first polymer matrix. Theplurality of fibers extend parallel to and are discontinuous along alength of the belt and arranged with one or more lengthwise extendinggaps between lengthwise adjacent fibers. A jacket substantially retainsthe tension member.

Additionally or alternatively, in this or other embodiments the tensionmember further comprises a plurality of fiber bundles secured to oneanother via a second polymer matrix, each fiber bundle including aplurality of fibers bonded in the first polymer matrix.

Additionally or alternatively, in this or other embodiments the secondpolymer matrix material is different from the first polymer matrixmaterial.

Additionally or alternatively, in this or other embodiments the tensionmember has a fiber density by volume of between 30% and 70%.

Additionally or alternatively, in this or other embodiments the fiberbundle includes fibers of non-uniform cross-sectional sizes and/orlengths.

Additionally or alternatively, in this or other embodiments the beltincludes one or more layers of fibers extending nonparallel to thelength of the belt.

Additionally or alternatively, in this or other embodiments the one ormore layers are disposed at an outermost belt surface.

Additionally or alternatively, in this or other embodiments theplurality of fibers are formed from one or more of carbon, glass,polyester, nylon, aramid or other polyimide materials.

Additionally or alternatively, in this or other embodiments the firstpolymer matrix is formed from a thermoset material or thermoplasticmaterial.

Additionally or alternatively, in this or other embodiments the belt hasan aspect ratio of belt width to belt thickness of greater than or equalto 3:2, with the plurality of tension members arranged across the beltwidth.

In yet another embodiment, a method of forming a tension member for anelevator system belt includes arranging a plurality of fibers into afiber bundle. The plurality of fibers extend parallel to a length of thebelt and have one or more lengthwise extending gaps between lengthwiseextending fibers. The plurality of fibers is bonded to a first polymermatrix.

Additionally or alternatively, in this or other embodiments the one ormore lengthwise extending gaps are formed by breaking lengthwiseadjacent fibers.

Additionally or alternatively, in this or other embodiments theplurality of fibers are formed from one or more of carbon, glass,polyester, nylon, aramid or other polyimide materials

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the present disclosure isparticularly pointed out and distinctly claimed in the claims at theconclusion of the specification. The foregoing and other features, andadvantages of the present disclosure are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1A is a schematic of an exemplary elevator system having a 1:1roping arrangement;

FIG. 1B is a schematic of another exemplary elevator system having adifferent roping arrangement;

FIG. 1C is a schematic of another exemplary elevator system having acantilevered arrangement;

FIG. 2 is a lengthwise cross-sectional view of an embodiment of anelevator belt for an elevator system;

FIG. 3 is a width-wise cross-sectional view of an embodiment of anelevator belt for an elevator system;

FIG. 4 is a lengthwise cross-sectional view of another embodiment of anelevator belt for an elevator system;

FIG. 5 is a lengthwise cross-sectional view of yet another embodiment ofan elevator belt for an elevator system;

FIG. 6 is a lengthwise cross-sectional view of an embodiment of atension member for an elevator belt for an elevator system; and

FIG. 7 is a plan view of an embodiment of a tension member for anelevator belt for an elevator system.

DETAILED DESCRIPTION

Shown in FIGS. 1A, 1B and 1C are schematics of exemplary tractionelevator systems 10. Features of the elevator system 10 that are notrequired for an understanding of the present invention (such as theguide rails, safeties, etc.) are not discussed herein. The elevatorsystem 10 includes an elevator car 12 operatively suspended or supportedin a hoistway 14 with one or more belts 16. The one or more belts 16interact with one or more sheaves 18 to be routed around variouscomponents of the elevator system 10. The one or more belts 16 couldalso be connected to a counterweight 22, which is used to help balancethe elevator system 10 and reduce the difference in belt tension on bothsides of the traction sheave during operation.

The sheaves 18 each have a diameter 20, which may be the same ordifferent than the diameters of the other sheaves 18 in the elevatorsystem 10. At least one of the sheaves 18 could be a drive sheave. Adrive sheave is driven by a machine 50. Movement of drive sheave by themachine 50 drives, moves and/or propels (through traction) the one ormore belts 16 that are routed around the drive sheave.

At least one of the sheaves 18 could be a diverter, deflector or idlersheave. Diverter, deflector or idler sheaves are not driven by themachine 50, but help guide the one or more belts 16 around the variouscomponents of the elevator system 10.

In many embodiments, the elevator system 10 may utilize a multiplicityof belts 16 for suspending and/or driving the elevator car 12. Inaddition, the elevator system 10 could have various configurations suchthat either both sides of the one or more belts 16 engage the one ormore sheaves 18 (such as shown in the exemplary elevator systems in FIG.1A, 1B or 1C) or only one side of the one or more belts 16 engages theone or more sheaves 18.

FIG. 1A provides a 1:1 roping arrangement in which the one or more belts16 terminate at the car 12 and counterweight 22. FIGS. 1B and 1C providedifferent roping arrangements. Specifically, FIGS. 1B and 1C show thatthe car 12 and/or the counterweight 22 can have one or more sheaves 18thereon engaging the one or more belts 16 and the one or more belts 16terminate elsewhere, typically at a pair of load carrying structureswithin the hoistway 14 (such as for a machineroomless elevator system)or within the machine room (for elevator systems utilizing a machineroom. The number of sheaves 18 used in the arrangement determines thespecific roping ratio (e.g. the 2:1 roping ratio shown in FIGS. 1B and1C or a different ratio). FIG. 1C also provides a so-called rucksack orcantilevered type elevator. The present invention could be used onelevator systems other than the exemplary types shown in FIGS. 1A, 1Band 1C.

FIG. 2 provides a schematic lengthwise cross-sectional view of anexemplary belt 16 construction or design. The belt 16 includes aplurality of fibers 24. The fibers 24 are discontinuous over a beltlength 26, having a number of breaks or gaps 28 between fibers 24 alongthe belt length 26. The plurality of fibers 24 may be arranged orstacked along a belt width 30 and/or a belt thickness 32, orientedgenerally such that a fiber length 34 is directed along the belt length26. The fibers 24 are bonding to a polymer matrix 36 to form a tensionmember 38 for the belt 16. One or more such tension members 38 may beencased in a polymer jacket 40 to form the belt 16. For example, in theembodiment shown in FIG. 3, the belt 16 includes three tension members38 encased in the jacket 40.

The fibers 24 may be formed of one or more of a number of materials,such as carbon, glass, polyester, nylon, aramid or other polyimidematerials. Further, the fibers 24 may be organized into a grouping, suchas a spun yarn. The matrix 36 may be formed of, for example a thermosetor thermoplastic material, while the jacket 40 may be formed from anelastomer material, such as thermoplastic polyurethane (TPU). Thetension member 38 is further configured to have a fiber 24 density of30% to 70% fibers 24 per unit of volume. In some embodiments, the fibers24 may vary in size, length or circumference and may further beintentionally varied to provide a selected maximum fiber 24 density

Referring again to FIG. 2, when the fibers 24 are arranged, the fibers24 are staggered such that a gap 28 does not extend continuously throughan entire belt thickness 32 or an entire belt width 30, so the beltretains a required lengthwise strength even though the fibers 24 arediscontinuous along the belt length 26. Further, the belt 16 withdiscontinuous fibers 24 has reduced bending stiffness along thelengthwise direction resulting in improved belt flexibility, andimproved damping properties compared to a belt with continuous fibers.Damping is improved via stress concentrations at the numerous fiber ends42 and, therefore, increased hysteretic energy losses at the gaps 28 andareas between the fibers 24. The improved damping properties improve theelevator ride comfort, especially for high rise installations.

Another embodiment is shown in FIG. 4. In this embodiment, the fibers 24are arranged into bundles 44 including multiple layers of fibers 24. Thebundles 44 may be arranged or stacked along the belt length 26 or alongthe belt width 30 or along the belt thickness 32. The bundles 44 areformed by bonding fibers 24 with a first polymer matrix 26 a. Thebundles 44 may then be formed into the tension member 38 by arrangingthe bundles 44 into a selected configuration, then bonding the bundles44 into the tension member 38 with a second polymer matrix 26 b. In someembodiments, the first polymer matrix 26 a is the same material as thesecond polymer matrix 26 b, while in other embodiments the first polymermatrix 26 a and the second polymer matrix 26 b are of differentmaterials to achieve a selected performance of the tension member 38. Inother embodiments, as shown in FIG. 5, non-continuous fibers 24 may becombined with a plurality of continuous fibers 46 to form a hybridtension member 38.

In some embodiments, the fibers 24 are discontinuous when bonded withthe first polymer matrix 26, while in other embodiments continuousfibers fed into the production machinery and after matrix impregnationand/or partial curing (cooling), the fibers are then broken into shortfibers 24 before the final cure (or solidification).

Referring now to FIGS. 6 and 7, the belt 16, or tension member 38, mayinclude one or more layers 48 of randomly-oriented fibers 24, with atleast a portion of the fibers oriented in a direction other than alongthe belt length 26. The random or off-length orientation of the fibers24 increases a belt strength across the belt width 30. The layers 48 maybe the outermost portions of the tension member 38 as shown in FIG. 6,or alternatively one or more layers 48 may be embedded in an interior ofthe tension member 38. Further, the fibers 24 of the layers 48 may beformed from a same material as the fibers 24 of the remainder of thetension member 38, or may be formed from a different material. Thelayers 48 can be either continuous or dis-continuous or combination ofboth.

In addition to the aforementioned reduced bending stiffness leading togreater belt flexibility, and also in addition to the better dampingperformance of the belt 16 with dis-continuous fibers 24, the belt 16has improved reparability as it is not necessary to retain fibercontinuity when making the repair.

While the present disclosure has been described in detail in connectionwith only a limited number of embodiments, it should be readilyunderstood that the present disclosure is not limited to such disclosedembodiments. Rather, the present disclosure can be modified toincorporate any number of variations, alterations, substitutions orequivalent arrangements not heretofore described, but which arecommensurate with the spirit and scope of the present disclosure.Additionally, while various embodiments of the present disclosure havebeen described, it is to be understood that aspects of the presentdisclosure may include only some of the described embodiments.Accordingly, the present disclosure is not to be seen as limited by theforegoing description, but is only limited by the scope of the appendedclaims.

1. A belt for suspending and/or driving an elevator car, comprising: atension member extending along a length of the belt, the tension memberincluding a plurality of fibers bonded in a first polymer matrix, theplurality of fibers extending parallel to and discontinuous along alength of the belt and arranged with one or more lengthwise extendinggaps between lengthwise adjacent fibers; and a jacket substantiallyretaining the tension member.
 2. The belt of claim 1, wherein thetension member further comprises a plurality of fiber bundles secured toone another via a second polymer matrix, each fiber bundle including aplurality of fibers bonded in the first polymer matrix.
 3. The belt ofclaim 2, wherein the second polymer matrix material is different fromthe first polymer matrix material.
 4. The belt of claim 1, wherein thetension member has a fiber density by volume of between 30% and 70%. 5.The belt of claim 1, wherein the fiber bundle includes fibers ofnon-uniform sizes.
 6. The belt of claim 1, wherein the belt includes oneor more layers of fibers extending nonparallel to the length of thebelt.
 7. The belt of claim 6, wherein the one or more layers aredisposed at an outermost belt surface.
 8. The belt of claim 1, whereinthe plurality of fibers are formed from one or more of carbon, glass,polyester, nylon, aramid or other polyimide materials.
 9. The belt ofclaim 1, wherein the first polymer matrix is formed from a thermosetmaterial or a thermoplastic material.
 10. The belt of claim 1, whereinthe belt has an aspect ratio of belt width to belt thickness of greaterthan or equal to 3:2, with a plurality of tension members arrangedacross the belt width.
 11. An elevator system comprising: an elevatorcar; one or more sheaves; and one or more belts operably connected tothe car and interactive with the one or more sheaves for suspendingand/or driving the elevator car, each belt of the one or more beltsincluding: a tension member extending along a length of the belt, thetension member including a plurality of fibers bonded in a first polymermatrix, the plurality of fibers extending parallel to and discontinuousalong a length of the belt and arranged with one or more lengthwiseextending gaps between lengthwise adjacent fibers; and a jacketsubstantially retaining the tension member.
 12. The elevator system ofclaim 11, wherein the tension member further comprises a plurality offiber bundles secured to one another via a second polymer matrix, eachfiber bundle including a plurality of fibers bonded in the first polymermatrix.
 13. The elevator system of claim 12, wherein the second polymermatrix material is different from the first polymer matrix material. 14.The elevator system of claim 11, wherein the tension member has a fiberdensity by volume of between 30% and 70%.
 15. The elevator system ofclaim 11, wherein the fiber bundle includes fibers of non-uniform sizes.16. The elevator system of claim 11, wherein the belt includes one ormore layers of fibers extending nonparallel to the length of the belt.17. The elevator system of claim 16, wherein the one or more layers aredisposed at an outermost belt surface.
 18. The elevator system of claim11, wherein the plurality of fibers are formed from one or more ofcarbon, glass, polyester, nylon, aramid or other polyimide materials.19. The elevator system of claim 11, wherein the first polymer matrix isformed from a thermoset material or thermoplastic material.
 20. Theelevator system of claim 11, wherein the belt has an aspect ratio ofbelt width to belt thickness of greater than or equal to 3:2, with theplurality of tension members arranged across the belt width.
 21. Amethod of forming a tension member for an elevator system belt,comprising: arranging a plurality of fibers into a fiber bundle, theplurality of fibers extending parallel to a length of the belt andhaving one or more lengthwise extending gaps between lengthwiseextending fibers; and bonding the plurality of fibers to a first polymermatrix.
 22. The method of claim 21, further comprising forming the oneor more lengthwise extending gaps by breaking lengthwise adjacentfibers.
 23. The method of claim 21, wherein the plurality of fibers areformed from one or more of carbon, glass, polyester, nylon, aramid orother polyimide materials